This invention relates to a label dispensing system which functions to retrieve the end label in a stack of labels and to move the label to a moving work piece, such as to a moving terry cloth towel which is about to have its cut edge folded over and sewn into a hem. The label is inserted into the hem before the stitching is formed in the hem.
It is customary to insert labels and the like in the hemmed edge of towels and of other manufactured products, and to sew the label into the hem. The hem can be folded over the label, or the edge of the product can have an overedge stitch which also attaches the label to the product. In the past, hemmed edges of towels and other products were formed by hand, with a sewing machine operator guiding the edge of the work piece through a folder and toward a sewing machine to fold the edge portion and to sew the fold closed. Labels were inserted by the operator into the hem as the hem was being formed and sewn closed.
More recently, automatic hemming systems have been developed which automatically hem the edges of sheet material. Examples of such automatic systems are shown in U.S. Pat. Nos. 3,773,002 and 3,906,878.
An example of a label dispenser which can be utilized to dispense a label to the hem of a towel, sheet or the like as the hem is being formed is illustrated in U.S. Pat. No. 4,157,692.
The reliable placement of labels in the hem of sheet material is difficult to accomplish. The equipment occasionally fails to dispense a label, the labels which are dispensed sometimes are not properly positioned on the work piece, and sometimes more than one label is dispensed at a time. Usually, the labels are arranged in a vertical stack and supported in a housing or tray, and the bottom label is pulled from the stack and moved to the work piece. When the stack of labels contains a large number of labels, the weight applied to the bottom label will be more than when the stack has been substantially depleted. This means that more force is required to remove the bottom label from a large stack than to remove the bottom label from a short stack. If too little force is applied to the bottom label of a large stack, it is likely that the label will not separate from the stack; however, if the removal force is increased and the stack depletes, it is more likely that the additional force applied to the bottom label in a short stack will withdraw more than one label from the stack at a time. Moreover, the weight applied to the bottom label in a stack tends to compact the labels so that if a suction device is applied to the bottom label to pull the label from the stack, the compact condition of the labels is likely to require a substantial amount of air suction to be applied to a label to withdraw the label from the stack, yet the increase in suction may tend to cause more than one label to be affected by the flow of air to the suction device, thereby pulling more than one label from the stack.
When the type of label being handled by a label dispenser is changed to a label that is stiffer or more limber, or to a label that is thicker or thinner than a previous label, the air suction utilized to draw the label away from the vertical stack usually must be modified so as to be compatible with the particular labels being dispensed.